Rebecca's Blog

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Endocrine disrupters in ocular surface disease - and paying attention to the unusual.

Are endocrine disrupters contributing to the increase in dry eye?

This paper was just published in a journal called Medical Hypotheses. This journal is pretty far out there - more about ideas than science, for sure, and it’s been embroiled in controversies at times. However, this subject matter actually seemed pretty timely to me.

The idea is that “endocrine disrupters”, certain natural or man-made chemicals in many products such as cosmetics, pesticides and, ahem, plastic packaging and metal food cans, may affect - among other things - our sex and thyroid hormones, both of which have roles to play in dry eye disease. In other words, they may be contributing to the increase in dry eye.

This study highlights the fact that unusual cases deserve special attention. (Ahem!)

When I read this bit in the abstract:

…The increasing frequency of dry eye and other ocular diseases indicates the need to better investigate the potential relationships beyond the isolated associations mentioned by patients and documented as rare case reports….

…My first response was, “Right on!” But then, I circled back to this key phrase:

… isolated associations mentioned by patients

…which struck me as awfully idealist. After all, unusual ocular surface disease associations can’t hope to be documented as case reports, much less have the relationships between them investigated, unless they’re actually heard and taken seriously.

How many of these potentially data-rich dry eye cases are dismissed by the physician as coincidental before the first twenty words are out of the patient’s mouth?

Not all dry eye is due to menopause, auto-immune disease or iatrogenic causes.

Today’s rarity may be tomorrow’s trend.

We need to carefully investigate the new and unusual cases so we can get ahead of the curve and improve prevention advice.

Abstract

Endocrine disruptors are a group of compounds that occur in increasing amounts in the environment. These compounds change the hormone homeostasis of the target organs regulated by those hormones, mostly by binding to their receptors and affecting their signaling pathways. Among the hormones altered by endocrine disruptors are sex hormones, thyroid hormones, and insulin. Studies have documented abnormalities in the reproductive and metabolic systems of various animal species exposed to endocrine disruptors. Endocrine disruptors can play a significant role in ocular diseases once hormone deficiency or excess are involved in the mechanism of that disease. Cataracts, dry eye disease and retinal diseases, such as macular hole and diabetic retinopathy, are some of the frequent problems where hormones have been implicated. We found that some compounds function as endocrine disruptors in the metabolism of body organs and systems. The increasing frequency of dry eye and other ocular diseases indicates the need to better investigate the potential relationships beyond the isolated associations mentioned by patients and documented as rare case reports. The evidence from case-control studies and experimental assays can provide the information necessary to confirm the endocrine effects of these chemicals in the pathophysiology of dry eye disease. We hypothesize that endocrine disruptors may contribute to the increase of ocular diseases, such as dry eye disease, in recent years.